Autonomous vehicles including robotic devices are becoming more prevalent today and are used to perform tasks traditionally considered mundane, time-consuming, or dangerous. As programming technology increases, so does the demand for robotic devices that can navigate around a complex environment or working space with little or no assistance from a human operator.
Autonomous vehicles and associated controls, navigation systems, and other related systems are being developed. For example, U.S. Pat. No. 6,594,844 discloses a Robot Obstacle Detection System, the disclosure of which is hereby incorporated by reference in its entirety. Additional robot control and navigation systems, and other related systems, are disclosed in PCT Published Patent Application No. WO 2004/025947 and in U.S. Pat. Nos. 6,809,490, 6,690,134, 6,781,338, 7,024,278, 6,883,201, and 7,332,890, the disclosures of which are hereby incorporated by reference in their entireties.
Many autonomous vehicles navigate a working space by moving randomly until an obstacle is encountered. Generally, these types of vehicles have on-board obstacle detectors, such as bump sensors or similar devices, which register contact with an obstacle. Once contact is made, command routines can direct the autonomous vehicle to move in a direction away from the obstacle. These types of systems, which are useful for obstacle avoidance, are limited in their ability to allow an autonomous vehicle to track its location within a room or other working environment. Other systems, often used in conjunction with bump sensors as described above, use an infrared or other detector to sense the presence of nearby walls, obstacles, or other objects, and either follow the obstacle or direct the vehicle away from it. These systems, however, are also limited in their ability to allow an autonomous vehicle to navigate effectively in a complex environment, as they only allow the vehicle to recognize when objects are in its immediate vicinity.
In more advanced navigation systems, an autonomous vehicle comprises an infrared or other type of transmitter, which directs a series of infrared patterns in horizontal directions around the autonomous vehicle. These patterns can be detected by a stationary receiver placed at or near a boundary of the working space, for example on a wall. A microprocessor can use the information from signals generated by the receiver to calculate where in the working space the autonomous vehicle is located at all times. Using such systems, the vehicle can navigate around an entire area. These systems, however, are best employed in working spaces where few objects are present that may interfere with the dispersed patterns of infrared signals.
Limitations of the above types of navigation systems are, at present, a hurdle to creating a highly independent autonomous vehicle that can navigate in a complex environment.